Resin lining is known as one of the methods of coating the surface of a material with a resin. Resin lining is usually employed for coating the inner surface of a pipe having a large diameter or a can with a resin for purposes including corrosion proofing, surface smoothing and life prolongation.
A method in which a resin powder is applied to the inner surface of a pipe having a large diameter, is dried, is melted under heat and is solidified by cooling to form a resin coating thereon is known as disclosed in, for example, JP-A-10-160090. It discloses in Example 2 a resin coating formed on the inner surface of a steel pipe having a diameter of 2,000 mm and a length of 4,000 mm by applying thereto a slurry composed of a resin powder and a solvent (hereinafter called the resin powder dispersion), melting the dispersion under heat and cooling it.
Attempts have been made to have a resin powder or minute resin particles adhere to the inner wall surface of a thin tube having an inside diameter of, say, 0.2 to 5 mm by filling the tube with a resin powder dispersion composed of the resin powder and a solvent, or a resin particulate dispersion composed of the minute resin particles and a solvent, and placing it in a position allowing the solvent to fall by gravity so that the solvent may be removed from the tube, leaving the resin powder or minute resin particles on the inner wall surface of the tube. The surface tension of the solvent is, however, so strong as not to allow it to fall down the inner wall surface of the tube and thereby leave the resin adhering thereto.
Therefore, it is hoped that technology be developed for coating the inner wall surface of a thin tube having an inside diameter of, say, 0.2 to 5 mm with a resin by having minute resin particles adhere thereto uniformly, melting them under heat and cooling them.